Compared with the traditional FinFET process, the gate-all-around transistor (GAAFET) introduces processes such as inner spacer and channel release, which must be achieved through precise lateral etching of the stacked structure. High-precision etching process control is one of the biggest challenges facing 3D integrated circuit manufacturing, and its process mechanism and regulation mechanism have received widespread attention in the scientific and industrial communities.
In response to the morphological defects and uniformity problems faced by the lateral selective etching process of the Si/SiGe stacked layers of the GAA inner wall structure, Chen Rui, a researcher at the EDA Center of the Institute of Microelectronics, worked with Li Junjie, a senior engineer at the Pioneer Center, Professor Wang Zhongrui of the Southern University of Science and Technology, and Professor Lado Filipovic of the Vienna University of Technology to propose a new simulation algorithm for the desorption and diffusion of Ge atoms, establish a continuous two-step dry etching process profile simulation model based on the Monte Carlo method, realize the lateral selective etching process profile simulation for the Si/SiGe six-layer stacked structure, and complete the tape-out experiment of the corresponding structure. By combining morphological simulation and transmission electron microscopy (TEM) characterization, the surface rounding phenomenon of the Ge layer etching and the influence mechanism of parameters such as cavity gas pressure on the uniformity of etching morphology were explored. This work provides theoretical and experimental references for clarifying the mechanism of the new principle etching process and optimizing process performance.
The research results were recently published in the top journal in the field of materials
, Small , with the title "A Two-Step Dry Etching Model for Non-Uniform Etching Profile in Gate-All-Around Field-Effect Transistor Manufacturing". Hu Ziyi, a master's student at the Institute of Microelectronics, is the first author of the paper, and Chen Rui, a researcher at the Institute of Microelectronics, Wei Yayi, and Professor Wang Zhongrui of the Southern University of Science and Technology are co-corresponding authors. The paper was also selected for oral presentation at
SISPAD 2024, the flagship conference in the field of TCAD simulation. In addition, related research results have also been published in journals such as ACS Applied Electronic Materials and Journal of Vacuum Science & Technology A , with Li Junjie, a senior engineer at the Institute of Microelectronics, as the co-corresponding author. This research was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences and the National Natural Science Foundation of China.
